With the widespread use of digital photography and digital storage, people are collecting large numbers of photos and copies of photos. In some instances, the photos may be hardcopy or hard print photos (stored in shoe boxes, photo albums and so forth) that were taken many years before, or may be soft, digitally stored copies of hard print photos that have been digitally scanned. While photos might be organized by either placing them in electronic folders or by tagging the photos (i.e., digitally labeling or identifying the photos with pertinent information, such as who is in the photo, where the photo was taken, and when it was taken), this can be very difficult because of the large number of photos that most people collect, because the amount of time that it takes to individually view and classify or identify each photo, and in some cases, because of the age of the photo or other factors that make it difficult to accurately identify the photo.
In some cases, when trying to identify old family photos, people may reference genealogical information, such as a family tree, and guess as to which person in a family tree the photo may relate to. But without knowing the date that the photo was taken, using a family tree to identify a photo can be difficult.